Internal-combustion engine



Dec. 28 1926.

s. A. Moss INTERNAL GOMBUSTI ON ENGINE Filed March 5, 1925 Fig.1.

2 Sheets-Sheet 1 Sanford A. Moss,

His Attorney.

Dec. 28, 1926. 1,612,143

s. A. mass I NTERNAL COMBUS TION ENGI NE Filed March 5, 1925 2 Sheets-Sheet 2 Fig. 5.

Inventor:

Sanford A. Moss,

5 His Attofzj Patented Dec. 28, 19 26.

UNITED STATES PATENT OFFICE."

SANFORD A. MOSS, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INTERNAL-COMBUSTION ENGINE.

Application filed March 5, 1925. Serial No. 13,026.

This application is a continuation in part of my application Serial No. 570,349, filed June 23, 1922.

The present invention relates to internal 6 combustion engines, particularly two-cycle engines, and has for its object to provide an improved means for scavenging such engines. It is applicable to either single cylinder or multi-cylinder engines.

For a consideration-of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawing, Fig. 1 is a diagrammatic view, partly in section, of an internal combustion engine provided with a scavenging means embodying my invention; Fig. 2 1s a diagrammatic plan view of the engine shown in Fi 1; and Fig. 3 is a diagrammatic view similar to Fig. 1 of a modification.

Referring to the drawing, Figs. 1 and 2, 5 indicates a cylinder of a two-cycle internal combustion engine here shown as being an engine of the high compression type. The cylinder is shown as being provided in the present instance with a main scavenging port 6, an auxiliary scavenging port 6, an exhaust port 7, and a fuel injector 8. In the cylinder is a piston 9 to which is connected a piston rod 10, the latter having the usual connection to the crank shaft in the well understood manner. A valve 11 is shown for controlling the admission of scavenging air from the scavenging air chamber 12 to the auxiliary port 6. It may be suitably operated from the crank shaft to open at the correct time for admit-V ting scavenging air, it being understood that 40 valve 11 will be closed during the down stroke and opened during a portion of the up stroke of the piston. The scavenging port 6 is controlled by the piston 9.

The foregoing engine structure may be drive such compressor by means of a turbine wheel operated by gases taken from a cylinder or cylinders of the engine. For driving the turbine wheel I utilize preferably gases discharged from a special port or ports located in advance of the regular exhaust port or ports, although as to certain aspects my invention is not limited to this arrangement. In Fig. 1, 14 indicates a centrifugal air compressor of any suitable type provided with an inlet 15 and a discharge conduit 16. Discharge conduit 16 is connected by'a pipe 17 to scavenging air chamber 12. The impeller of the compressor is mounted on a shaft 18 carried on a. bearing 19. On an end of shaft 18 is mounted a turbine wheel 20 provided with a ring of buckets 21 of any suitable struc ture. In one or each of the cylinders 5 in advance of port 7 is a special port 22 which communicates with a nozzle box or manifold 23 suitably fixed to cylinder 5. Nozzle box 23 is provided with one or more nozzles 24 arranged to discharge exhaust gases against bucket ring 21 to effect rotation of turbine wheel 20 in the well understood manner. Port 22 communicates with'nozzle box 23 through a passage 25 which may be provided with suitable weighted check valve means 26 which opens outwardly. This valve may be operated in any suitable manner. as being biased towards closed position by its weight and opened by the gas pressure. When the engine is in operation the piston on its out stroke uncovers port 22 prior to the time the scavenging and exhaust ports are uncovered and while there is still considerable pressure left in the cylinder so that a certain amount of gases escape through port 22 to nozzle box 23 and are directed by nozzle means 24 against the buckets of the turbine wheel. A certain pressure will be built up in the nozzle box and this pressure will be sufiicient to maintain the turbinewheel at a high speed so that the compressor 14 will deliver a suitable quantity of air at the desired pressure for scavenging the cylinder or cylinders. Preferably all the engine cylinders will be provided with special ports 22 since by this arrangement a more even pressure will be maintained in the nozzle box or manifold 23. However, the specific arrangement used In the present instance it is shown will depend upon the particular conditions met with and the total number of" engine cylinders in the engine. The compressor will maintain the desired scavenging air pressure in chamber 12 so that when piston t) uncovers ports 6 and 7 the scavenging air will rush through the cylinder to force out the spent gases and fill the cylinder with air. It' the engine is of a type utilizing auxiliary valve controlled scavenging ports, the arrangement will be such that valve 11 will be opened during the return stroke of the piston to admit a final charge of scavenging air. The valve 26 serves to close port 22 to prevent the flow of gases from the nozzlebox back into the cylinder or from the cylinder to the nozzle box during the compression stroke. It. will also prevent gases passing into a cylinder when another cylinder is supplying gas at a higher pressure. It will be understood, of course, that in place of a check valve I may use any other type of valve found desirable.

In Figs 3 I have shown a modification wherein in addition to the port 22 I provide a special exhaust port 30 which is slightly in advance of the regular exhaust port 7 and through which the major portion of the exhaust gases pass. Exhaust port 30 communicates with a chamber 31 from which leads two conduits 32 and 33. Conduit 32 conveys exhaust gases to a port 34 communicating with the atmosphere and conduit 33 conveys exhaust gases to a set of nozzles 35 which direct the gases against the buckets of turbine wheel 20. Conduits 32 and 33 are controlled by two interconnected valves 36 and 37, the arrangementbeing such that when one valve is closed the other is open. The arrangement is such that during the firing stroke valve 36 is closed and valve 37 is open so exhaust gases may pass to the nozzles 35, while during the compression stroke valve 36 is open and valve 37 is closed so that port 30 is connected to atmosphere. Valves 36 and 37 may be operated by any suitable means so as to be opened and closed at the correct times. In the present instance they are shown as being operated by the pressure of the exhaust gases. To this end the two valves 36 and 37 are connected together by a curved rod 38 and the valve structure thus formed is pivoted at 39, the arrangement being such that the weight of the valve structure biases it to a position wherein valve 37 is closed and valve 36 is open. On the down or firing stroke of the piston, the exhaust gases discharging through port 30, strike valve 37 and force it open, this action taking place because the exposed area of valve 37 is greater than that of valve 36. Valve 37 will be held open and valve 36 will be held closed until the exhaust gas pressure decreases to a value in the neigh borhood of atmospheric pressure whereupon valve '37 will fall by gravity to closed position at the same time opening valve 36. Port 30 is then connected to atmosphere by way of port 34. The exhaust port'7 is connected to atmosphere through a passage 40. and port 41. \Vith this arrangement 1 utilize the major portion of the exhaust gases for driving the turbo-compressor.

In connection with the construction illustrated in Fig. 3, 1 have shown a modilication wherein the turbine wheel 20 drives compressor mcans which'delivers scavenging air at two ditt'erent pressures, such compressor means comprising in the present instance two centrifugal compressors 42 and 43. The

discharge side of compressor 42 is connected by a conduit 44 to a chamber 45 from which scavenging air is supplied through valve 11 to scavenging port (3.while the discharge side of compressor 43 is connected by a conduit 46 to the scavenging port means 6. Compressor 42 is preferably designed so that it furnishes air at a pressure somewhat higher than that furnished by compressor 43 so that the final charge of scavenging air supplied to the cylinder through port 6 serves to provide initially in the cylinder at higher pressure and hence a greater quantity by weight of air. This serves to supercharge the cylinder. It will be understood, of course, that as pointed out above in connecfion with Fig. 1, valve 26 serves to prevent scavenging air supplied through port 6 from flowing out through port means 25 and also prevents gases flowing from nozzle box 23 back to the cylinder. Valve 26 is biased toward closed position'by its weight and this, plus the pressure in nozzle box 23 is sufficient always to hold valve 26 closed against the scavenging air pressure which, of course, is much lower than the explosion pressure present in the cylinder when port means 22 is uncovered on the firing stroke.

A turbo-compressor set is inherently a high speed apparatus, operating at a speed of the order of 10,000 revolutions per minute, for example. It will therefore be much lighter than any type of separate compressor set such as a reciprocating compressor and will have a lower first cost. Furthermore, as is well known, centrifugal compressor and turbine apparatus requires much less maintenance than reciprocating compressor apparatus.

Apparatus embodying my invention has the further advantage that it is inherently self-governing and will automatically supply the correct amount of scavenging air. With increase in load more scavenging air is required but at the same time there will he more products of combustion at a higher pressure.

Hence the gas turbine will be operated at higher speed and so increase the pressure and amount of scavenging air. With delllll ple of operation of m with the apparatus which I now consider to In accordance with the provisions of the patent statutes, I have described the princiinvention, together represent the best embodiment thereof, but

' a I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out. by other means. 3

What I claim as new and desire to secure by Letters Patent of the United States, is

1. The combination with 'a two-cycle internal combustion engine comprising a cylinder having scavenging and exhaust ports and a piston. of a centrifugal air compressor having its discharge side connected to the scavenging port, a turbine wheel for driving the compressor, walls forming a gas chamber and providing means for directing actuating gases to the turbine wheel, and a port in the cylinder which is opened immediately in advance of the opening of the exhaust port for supplying gases to said chamber, said port being controlled by the piston.

2. The combination with a two-cycle internal combustion engine comprising a cylinder having scavengmg and exhaust ports and a piston, of a centrifugal air compressor having its discharge side connected to the scavenging port, a turbine wheel for driving the'compressor, a nozzle box having nozzle means for directing actuating gases to the turbine wheel, a port in the cyllnder which is opened immediately in advance of the opening of the exhaust port for supplying ases to the nozzle box, said port being controlled by the piston, and a non-return valve means for preventing flow of gases from the nozzle box toward the cylinder.

3. The combination with a two-cycle internal combustion engine comprising a cylinder having scavenging and exhaust ports and a piston, of a centrifugal air compressor having its discharge side connected .to the scavenging port, a turbine wheel for driving the compressor, a nozzle box having nozzle means for directing actuating gases to the turbine wheel, a port in the cylinder which is opened immediately in advance of the opening of the exhaust port for su plying gases to the nozzle box, said port eing controlled by the piston and a non-return valve means controlled by the pressure of the gases in the nozzle box for covering and uncovering said last-named port to prevent flow of gases from the nozzle box toward the cylinder.

4. The combination with a two-cycle internal combustion engine, comprising a cylinder having scavenging and exhaust ports and a piston, of a centrifugal air compressor having ts discharge side connected to the scavenging port, a turbine wheel for driving the compressor, nozzle boxes having nozzle means for directing actuating gases to the turbine wheel, and a plurality of ports in the cylinder which are opened immediately in advance of the opening of the exhaust port for supplying gases to the nozzle boxes, said ports being controlled by the piston.

5. The combination with a two-cycle internal "combustion engine comprising a cylinder having scavenging and exhaust ports and a piston, of a centrifugal air compressor having its discharge side connected to the scavenging port, a turbine wheel tor driving the compressor, nozzle boxes having nozzle means for directing actuating gases to the turbine wheel, a plurality of ports in the cylinder which are opened immediately in advance of the opening of the exhaust port for supplying gases to the nozzle boxes, said ports being controlled by thepiston and nonreturn valve means for preventing flow of gases from the nozzle box toward the cyliner.

6. The combination with a two-cycle internal combustion engine comprising a cylinder having scavenging and exhaust ports and a piston, of a centrifugal air compressor having its discharge side connected to the scavenging port, a turbine wheel for driving the compressor, and a plurality of exhaust ports in the cylinder arranged one in advance of another for supplying gases to actuate the turbine wheel, said ports being controlled by the piston and being opened immediately in advance of the opening of the exhaust port.

7, The combination with a two-cycle internal combustion engine comprising a cylinder having scavenging and exhaust ports and a piston, of a centrifugal air compressor having its discharge side connected to the scavenging port, a turbine wheel for driving the compressor, a plurality of exhaust ports in the cylinder, said ports being controlled by the piston and being opened Immediately in advance of the opening of the exhaust port, a nozzle box to which one of said exhaust ports is connected, at second nozzle box, and valve means for connecting another of said exhaust ports to either the second nozzle box or to atmosphere.

8. The combination with a two-cycle internal combustion engine comprising a cylinder structure having two sets of scavenging ports one of which is opened in advance of the other, and exhaust port means, of centrifugal air compressor means provided with two discharge conduits for receiving air of different pressures from the compressor means, means connecting the discharge conduits to said two sets of scavenging ports, a turbine wheel for driving the compressor means, and means for supplying ases from the clvlindcr structure to drive the turbine wheel.

9. The combination with a two-cycle in ternal combustion engine comprising a piston and a cylinder structure having two sets of s avenging ports one of which is opened in advance of the other, and exhaust port means. of centrifugal air compressor means provided with two discharge conduits for receiving air of ditierent pressures from the compressor means, means connecting the discharge conduits to said two sets of scavenging ports, a turbine wheel for driving the compressor means, and port means in the cylinder structure which is opened in ad- Vance of opening the said exhaust port means for supplying gases to drive the turbine wheel, said port means being controlled by the piston.

10. The combination with a two-cycle intern-a1 combustion engine comprising a cylindcr structure having two sets of scavenging ports one of which is opened in advance of the other, and exhaust port means, of air compressor means provided with two discharge conduits for receiving air of different pressures from the compressor means, means connecting the discharge conduits to said two sets of scavenging ports, and means for driving said compressor means.

11. The combination with a two-cycle internal combustion engine having two sets of scavenging ports. one in advance of the other. of centrifugal compressor means for sul'iplying air to each of said sets of ports, the air supplied to one of said sets being of a pressure higher than that supplied to the other, and means actuated by gases from the engine for operating said compressor means.

In witness whereof, I have hereunto set my hand this 3rd day of March, 1925.

' SANFORD A. MOSS. 

